Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
19 results
Search Results
Article Citation - WoS: 18Citation - Scopus: 15Search for a Fermiophobic Higgs Boson in Pp Collisions at ?s = 7 Tev(Springer Verlag, 2012) CMS Collaboration; Karapınar, GülerCombined results are reported from searches for a fermiophobic Higgs boson in the γγ WW, and ZZ decay modes in proton-proton collisions at √s = 7TeV. The explored Higgs boson mass range is 110-300 GeV. The data sample corresponds to an integrated luminosity of 4.9-5.1 fb-1. A fermiophobic Higgs boson is excluded at 95% confidence level in the mass range 110-194 GeV, and at 99% confidence level in the mass ranges 110-124.5 GeV, 127-147.5 GeV, and 155-180 GeV.Article Citation - WoS: 6Citation - Scopus: 30Search for Resonant T¯t Production in Lepton+jets Events in Pp Collisions at ?s=7 Tev(Springer Verlag, 2012) CMS Collaboration; Karapınar, GülerA model-independent search for the production of heavy resonances decaying into top-antitop quark pairs is presented. The search is based on events containing one lepton (muon or electron) and at least two jets selected from data samples corresponding to an integrated luminosity of 4.4-5.0 fb -1 collected in pp collisions at √s =7 TeV. Results are presented from the combination of two dedicated searches optimized for boosted production and production at threshold. No excess of events is observed over the expected yield from the standard model processes. Topcolor Z′ bosons with narrow (wide) width are excluded at 95% confidence level for masses below 1.49 (2.04) TeV and an upper limit of 0.3 (1.3) pb or lower is set on the production cross section times branching fraction for resonance masses above 1 TeV. Kaluza-Klein excitations of a gluon with masses below 1.82 TeV (at 95% confidence level) in the Randall-Sundrum model are also excluded, and an upper limit of 0.7 pb or lower is set on the production cross section times branching fraction for resonance masses above 1 TeV.[Figure not available: See fulltext.] © 2012 CERN for the benefit of the CMS collaboration.Article Citation - WoS: 144Citation - Scopus: 152Search for Dark Matter and Large Extra Dimensions in Monojet Events in Pp Collisions at ?s = 7 Tev(Springer Verlag, 2012) CMS Collaboration; Karapınar, GülerA search has been made for events containing an energetic jet and an imbalance in transverse momentum using a data sample of pp collisions at a center-of-mass energy of 7 TeV. This signature is common to both dark matter and extra dimensions models. The data were collected by the CMS detector at the LHC and correspond to an integrated luminosity of 5.0 fb -1. The number of observed events is consistent with the standard model expectation. Constraints on the dark matter-nucleon scattering cross sections are determined for both spin-independent and spin-dependent interaction models. For the spin-independent model, these are the most constraining limits for a dark matter particle with mass below 3.5 GeV/c 2, a region unexplored by direct detection experiments. For the spin-dependent model, these are the most stringent constraints over the 0.1-200 GeV/c 2 mass range. The constraints on the Arkani-Hamed, Dimopoulos, and Dvali model parameter M D determined as a function of the number of extra dimensions are also an improvement over the previous results.Article Citation - WoS: 86Citation - Scopus: 109Study of Z Boson Production in Pbpb Collisions at ?s Nn=2.76tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliA search for Z bosons in the μ+μ- decay channel has been performed in PbPb collisions at √sNN=2.76TeV with the CMS detector at the LHC, in a 7.2μb-1 data sample. The number of opposite-sign muon pairs observed in the 60-120GeV/c2 invariant mass range is 39, corresponding to a yield per unit of rapidity (y) and per minimum bias event of [33.8±5.5(stat)±4.4(syst)]×10-8, in the |y|<2.0 range. Rapidity, transverse momentum, and centrality dependencies are also measured. The results agree with next-to-leading order QCD calculations, scaled by the number of incoherent nucleon-nucleon collisions. © 2011 American Physical Society.Article Citation - WoS: 243Citation - Scopus: 216Indications of Suppression of Excited? States in Pb-Pb Collisions at Snn2.76 Tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliA comparison of the relative yields of Υ resonances in the μ+μ- decay channel in Pb-Pb and pp collisions at a center-of-mass energy per nucleon pair of 2.76TeV is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above 4GeV/c and pseudorapidity below 2.4, the double ratio of the Υ(2S) and Υ(3S) excited states to the Υ(1S) ground state in Pb-Pb and pp collisions, [Υ(2S+3S)/Υ(1S)]Pb-Pb/[Υ(2S+3S)/Υ(1S) ]pp, is found to be 0.31-0.15+0.19(stat)±0.03(syst). The probability to obtain the measured value, or lower, if the true double ratio is unity, is calculated to be less than 1%. © 2011 American Physical Society.Article Citation - WoS: 130Citation - Scopus: 108Measurement of the T-Channel Single Top Quark Production Cross Section in Pp Collisions at ?s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliElectroweak production of the top quark is measured for the first time in pp collisions at √s=7TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36pb-1. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data. The second approach uses a multivariate analysis technique to probe the compatibility with signal topology expected from electroweak top-quark production. The combined measurement of the cross section is 83.6±29.8(stat+syst)±3.3(lumi) pb, consistent with the standard model expectation. © 2011 CERN.Article Citation - WoS: 111Citation - Scopus: 97Missing Transverse Energy Performance of the Cms Detector(IOP Publishing Ltd., 2011) Karapınar, Güler; Demir, Durmuş AliDuring 2010 the LHC delivered pp collisions with a centre-of-mass energy of 7 TeV. In this paper, the results of comprehensive studies of missing transverse energy as measured by the CMS detector are presented. The results cover the measurements of the scale and resolution for missing transverse energy, and the effects of multiple pp interactions within the same bunch crossings on the scale and resolution. Anomalous measurements of missing transverse energy are studied, and algorithms for their identification are described. The performance of several reconstruction algorithms for calculating missing transverse energy are compared. An algorithm, called missing-transverse-energy significance, which estimates the compatibility of the reconstructed missing transverse energy with zero, is described, and its performance is demonstrated. © 2011 CERN for the benefit of the CMS collaboration, published under license by IOP Publishing Ltd. SISSA.Article Citation - WoS: 242Citation - Scopus: 228Measurements of Inclusive W and Z Cross Sections in Pp Collisions at ?s = 7 Tev the Cms Collaboration(Springer Verlag, 2011) Karapınar, Güler; Demir, Durmuş AliMeasurements of inclusive W and Z boson production cross sections in pp collisions at √s = 7 TeV are presented, based on 2.9 pb-1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give σ(pp → WX) × B(W → l?) = 9.95 ± 0.07 (stat.) ± 0.28 (syst.) ± 1.09 (lumi.) nb and σ(pp → ZX) × B(Z → l +l-) = 0.931 ± 0.026 (stat.) ± 0.023 (syst.) ± 0.102 (lumi.) nb, where l stands for either e or μ. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.Article Citation - WoS: 519Citation - Scopus: 401Determination of Jet Energy Calibration and Transverse Momentum Resolution in Cms(IOP Publishing Ltd., 2011) Karapınar, Güler; Demir, Durmuş AliMeasurements of the jet energy calibration and transverse momentum resolution in CMS are presented, performed with a data sample collected in proton-proton collisions at a centre-of-mass energy of 7TeV, corresponding to an integrated luminosity of 36pb-1. The transverse momentum balance in dijet and γ/Z+jets events is used to measure the jet energy response in the CMS detector, as well as the transverse momentum resolution. The results are presented for three different methods to reconstruct jets: a calorimeter-based approach, the "Jet-Plus-Track" approach, which improves the measurement of calorimeter jets by exploiting the associated tracks, and the "Particle Flow" approach, which attempts to reconstruct individually each particle in the event, prior to the jet clustering, based on information from all relevant subdetectors.Article Citation - WoS: 51Citation - Scopus: 58Search for New Physics With a Monojet and Missing Transverse Energy in Pp Collisions at ?s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliA study of events with missing transverse energy and an energetic jet is performed using pp collision data at a center-of-mass energy of 7 TeV. The data were collected by the CMS detector at the LHC, and correspond to an integrated luminosity of 36pb-1. An excess of these events over standard model contributions is a signature of new physics such as large extra dimensions and unparticles. The number of observed events is in good agreement with the prediction of the standard model, and significant extension of the current limits on parameters of new physics benchmark models is achieved. © 2011 CERN.